Asking if someone or something cares is not a question of physical reality.
Firstly, how do you know that physical reality exists?
Secondly, assuming physical reality does exist, what would lead you to think that the capacity for cognition is not determined by physical features of reality?
Again, do you think there is any question over whether or not plants have thoughts and feelings? Are we compelled to accept panpsychism because we cannot absolutely rule out that rocks might be conscious?
That's not a measurable physical reality, you're trying to use guesses about subjective feelings as a standard of physical reality rather than... you know... the physical reality of being human.
Oof, that is desperate.
Okay, for the sake of argument let's accept your point here. Let's accept put aside any question about the capacity for cognition, and focus purely on the physical state of being human.
And let's also accept that a fertilized human embryo is a human, and that we are obliged to assume that possesses a will and personhood equivalent to our own even if we cannot see or experience that personhood directly, merely on the basis that we cannot directly experience the falsification of that assumption.
Now here's a question. Does it actually matter whether that embryo is alive?
What is the difference between a living human and a dead human? There are physical differences in the metabolic processes, but on the basic level of physical reality both are still human. Dead people do not appear to possess the capacity for cognition or consciousness, but we've decided that doesn't matter since we can't ever know whether those exist anyway.
In fact, if we follow your logic, we have to assume that because corpses are human, they must possess a will and personhood equivalent to our own. Even if they don't seem like they do, we cannot definitively rule out the idea that corpses have thoughts. This means that cremating them should be considered murder, burying them in the ground should be considered a horrifying form of torture. After all,
I wouldn't want to be buried in a wooden box or burned up in a furnace, so we must assume that a corpse, being human like me, would not want these things either and that inflicting it on them is a terrible violation of their rights as individuals..
Now, let's go back to the fundamental mistake you made, which was assuming that there can be an objective understanding of physical reality distinct from our subjective thoughts. Assuming all human minds are the same as mine, then no human can experience or interact with physical reality outside of the medium of their own senses and cognition. The idea that some objects in reality are human and others are not is a thought that requires a mind to think it. Even more obviously, the idea that being alive and/or conscious is preferable to being dead and/or in a coma is a cognitive bias introduced by our inability to imagine ourselves outside of the state of life or consciousness, since being alive and conscious is all we have ever experienced. We cannot remove that cognitive bias from human experience, even if it is "subjective", because consciousness is a precondition of our ability to engage with physical reality.
So, if I am basing my understanding of the needs and will of other humans on my own, then I cannot remember being an embryo. I was not conscious at that point. I cannot understand what I would want at that point in my existence because I wasn't there. Had I died at that point, it might have mattered to other people (probably not) but it wouldn't have mattered to me.
You cannot have it both ways. You cannot insist that we adhere to the physical reality of being human to determine personhood and then simultaneously demand that we empathize with a state that is outside of our capacity to experience the physical reality of being human.
Miscarriages are tragedies.
"Tragedy is when I cut my finger, comedy is when you fall into an open sewer and die."
Again, you can't have this cake and eat it.
Some poeple, funny enough, are trying to make religious arguments for abortion.
And?
There is nothing inherently wrong with basing your own life, decision and ethics on religious dogma. It is your life to dispose of as you see fit, even in ways others might think are silly and unreasonable. If you want to believe that it is wrong to have an abortion, then by all means believe that. But if you want to claim that this belief is the only reasonable belief, then you have stepped into a world that really should have higher standards, and wrapping the argument in the mangled corpse of idealism is not going to help as much as you think.
No, none of that follows, because you are not those things.
How do you know?